1. Technical Field
The present invention relates to a light emitting device that uses a variety of light emitting elements, an electronic apparatus including the light emitting device, and a manufacturing method of the light emitting device.
2. Related Art
In recent years, a top emission method light emitting device in which an organic EL (electro luminescence) element as a light emitting element is formed on a substrate, and the emitted light of the light emitting element is extracted to the opposite side of the substrate has been frequently used as a display device, and the like of an electronic apparatus. The top emission method is a method having a high utilization efficiency of light, in which a reflecting layer is formed between a first electrode (for example, anode) formed in the substrate side and the substrate while interposing the light emitting element, and light is extracted from a second electrode (for example, cathode) side where the light emitting element is interposed.
In the light emitting device of the top-emission scheme, a technique (for example, SID2010 P-146/S. Lee, Samsung Mobile Display Co., Ltd) which may enhance light extraction efficiency by resonating light having a predetermined wavelength between the second electrode and the reflecting layer using a white organic EL element has been disclosed. In this technique, when a peak wavelength in a resonance structure is denoted as λ, an optical distance of the second electrode from the reflecting layer is denoted as D, a phase shift in the reflection by the first electrode is denoted as φL, a phase shift in the reflection by the second electrode is denoted as φU, and an integer is denoted as m, an optical structure satisfying the following equation has been suggested.D={(2πm+φL+φU)/4π}λ  (1)
In particular, in the above equation (1), when m=0 is satisfied, light having a wide wavelength can be extracted with some efficiency while simplifying an array structure in the organic EL element, and therefore, a low cost light emitting device may be realized, and high-definition pixels may be to be created easily.
However, in the light emitting device of an optical structure obtained when m=0 is satisfied in the above equation (1), light of all regions of a red region, a green region, and a blue region is extracted, and therefore it is necessary that color separation of each of a red pixel, a green pixel, and a blue pixel is performed by a color filter, or the like. Accordingly, there has been a problem that a bandwidth of an emission spectrum on an observation side is wide resulting in poor color purity. In addition, there has been a problem that when compared in each of a red wavelength region, a green wavelength region, and a blue wavelength region, light extraction efficiency is reduced. As a result, there has been a problem that the power consumption of the light emitting device is increased, and light extraction efficiency is a disadvantageous as panel characteristic.
In addition, in order to improve the light extraction efficiency, it may be considered that a structure is changed for each pixel of each color, for example, the above described optical distance D is changed for each pixel of each color, and the like; however, in a manufacturing method of the light emitting device in the related art, the number of manufacturing processes is increased resulting in an increase in manufacturing costs.